Cell Structure and Organelles

Cell wall

functions to protect and support cells

made of a rigid material called cellulose in plants

animal cells don’t have cell walls

Cell Membrane

protects the cell

controls the movement of materials in and out of the cell (selectively permeable)

found in all cells

The cell membrane is made of phospholipids that are constantly moving.

Small molecules (e.g. CO2, O2, H2O) can diffuse through the phospholipids unassisted.

Proteins are embedded in the membrane that act as channels to move larger molecules in and out.

Cell Membrane cont.

Cytoplasm

The cytoplasm is everything inside the cell membrane, but outside the nucleus.

The cytoplasmcytoplasm is a jelly-like substance made mostly of water that fills the cell.

Organelles are located in the cytoplasm.

Nucleus and Nucleolus

Nucleus:

control center of the cell

contains chromosomes (made of DNA)

Nucleolus:

a dense area (darker area) within the nucleus

ribosomes are produced in the nucleolus

Mitochondrion

tiny, oval-shaped organelle that provides cells with energy (ATP)

mitochondria are the site of aerobic cellular respiration

ATP is used by other organelles for energy for cell processes

____________ + _________+ ________ ________ + ____________

Ribosome

ribosomes are microscopic spheres attached to the endoplasmic reticulum or floating in the cytoplasm

ribosomes make proteins

Endoplasmic Reticulum

a twisting network of canals

functions to transport materials throughout the cell

may have ribosomes attached to it (rough ER); smooth ER has no ribosomes attached

Golgi Apparatus

flattened sacs that produce vesicles (transport sacs)

they function to modify and store cellular secretions

(e.g. proteins)

Lysosome

saclike structure formed by the Golgi apparatus

contains enzymes that can break down large molecules or worn out cell parts

Vacuole

fluid-filled space containing water, sugar, and proteins

helps with water regulation in plants

vacuoles can also store food or help some organisms move

Centriole

small protein structures critical to cell division (paired)

not found in plant cells

Chloroplast

found only in green plants and some protists

Contains the light sensitive protein pigment chlorophyll

CO2 + H2O + sunlight sugar + O2

Chloroplast

convert sunlight into food for the cell via photosynthesis

____________ + _________+ ________ ________ + ____________

Cilia and Flagella

fine protein fibres used for locomotion

Cilia: short, may be numerous on cell surface

Flagella: long, usually few in number on cell surface

Cytoskeleton

protein fibres network that help anchor organelles in place and give structure to the cell

Plant Cell

electron micrograph of a typical plant cell

What structures are found only in plant cells?

cell wall large vacuole chloroplast

Animal Cell

electron micrograph of a typical animal cell

What structures are found only in animal cells?

cilia flagella centrioles

What structures are found in both plant and animal cells? What

structures are found in both?

cell membrane

cytoplasm

nucleus/nucleolus

mitochondrion

ribosomes

endoplasmic reticulum

lysosomes

golgi apparatus

cilia, flagella; centrioles